Circuit breakers have long been used in industrial and residential applications to prevent damage to the loads connected to them and the building structures in which the loads are located. Normally, when an electrical fault or a current overload condition is sensed in a particular circuit, the breaker protecting that circuit “trips” and creates a physical disconnect in the circuit, thereby preventing the flow of electricity. To resume electrical flow to the circuit, the operator must physically reconnect the circuit breaker, typically by throwing a mechanical switch back to a closed position. These detection systems work automatically, tripping circuits only when certain conditions are satisfied.
However, an energy supplier or consumer may want to control energy flow deliberately to certain loads or circuits at such times as are desired, even when no fault or overload condition is detected. To do so, some way of remotely controlling the connections across the loads must be provided. But in the case of power line communication techniques, communication with any devices on the load side of the circuit breaker cannot occur if it has been tripped or if the electrical contacts inside the circuit breaker are otherwise separated. Thus, as soon as a circuit breaker trips, no further data can be collected on electrical devices connected to that circuit breaker nor can any further instructions be transmitted to change the behavior of the connected electrical devices. There is therefore a need to maintain the communication link from the utility or line side of the circuit breaker to the load side of the circuit breaker even when the circuit breaker has physically disconnected the branch circuit.
Another related need involves managing the loads or electrical devices connected to circuit breakers within a home or other facility in a way that is flexible and adaptable to both the homeowner and the power company. Homes typically can obtain their power from various sources, such as the power company, a backup generator, or an alternative power source like solar power arrays. Electrical devices (referred to as loads) within the home draw varying levels of electrical power at different times of the day and at different times of the year. Furthermore, electrical devices can be categorized and prioritized based on their consumption behavior (some loads cycle on and off throughout the day, other loads draw lots of power when they turn on) and importance (a life-saving medical device would be more critical than a swimming pool motor). For example, an oven can be used year-round and most frequently around dinnertime. An air conditioning unit can be used heavily during the summer months and not at all during the winter months. Data on the usage and properties of these and other electrical devices throughout the home can be collected over a period of time to create a set of historical data that reflects the usage patterns, usage frequency, usage levels of each device, and other properties about the electrical device.
During peak times in the summer months, the power company may wish to limit or reduce peak power consumption. Other emergency situations may call for a reduction or change in power consumption, such as adverse weather conditions or utility equipment failure. One approach to reducing power consumption is to initiate rolling blackouts, but this inconveniences homeowners and renders entire neighborhoods without power. What is needed, therefore, is an adaptive load management algorithm that overcomes these and other disadvantages. The present invention addresses this and other needs, as more fully described below.